The suction ring used to create the LASIK flap raises the pressure inside the eye to dangerous levels. Elevated intraocular pressure is associated with damage to the optic nerve and glaucoma.
Thorough evaluation of glaucoma patients vital before refractive procedures
OSN SuperSite Top Story 6/17/2008
From the article: In addition, he noted the importance of avoiding, if possible, any type of microkeratome suction ring in eyes with optic neuropathy, as the rings are designed to increase IOP, which could lead to visual field loss after refractive procedures.
Surgeons must be aware of glaucoma risk after refractive surgery
OSN SuperSite Top Story 3/25/2008
From the article: The risk of glaucoma after refractive surgery procedures should not be underestimated, according to one surgeon speaking here at the Alicante Refractiva International meeting. "I have to play the part of devil's advocate by speaking about this topic in a refractive surgery meeting," said José Belda, MD, of Vissum Institute in Alicante. "Still, we have to consider that what we see is only the tip of the iceberg, and below it we may have a large quantity of patients presenting this problem in the future..." Meanwhile, suction can be a problem with LASIK. The vacuum phase is short, but pressure values are high — between 60 mm Hg and 90 mm Hg — and can reach as high as 200 mm Hg as the blade presses against the cornea, according to Dr. Belda.
Ophthalmology 2001 Apr;108(4):660-5
Laser in situ keratomileusis-induced optic neuropathy.
Cameron BD, Saffra NA, Strominger MB.
Division of Ophthalmology, Maimonides Medical Center, Brooklyn, New York. Department of Ophthalmology, NYU Medical
Center, New York, New York. Department of Ophthalmology, SUNY Health Science Center at Brooklyn, Brooklyn, New York.
OBJECTIVE: To report a case of bilateral optic neuropathy after bilateral laser-assisted in situ keratomileusis (LASIK) surgery.
DESIGN: Observational case report.
METHODS: Complete eye examination with detailed evaluation of the optic nerve, detailed medical history, stereo disc photographs, GDx Nerve Fiber Analyzer testing, Humphrey 24-2 SITA visual field testing, diurnal intraocular pressure measurement, serologic evaluation, and magnetic resonance imaging of the brain and orbits.
MAIN OUTCOME MEASURES: Optic nerve status, visual field status, and visual acuity.
RESULTS: A subject with previously healthy optic nerves had bilateral optic neuropathy develop after LASIK surgery. This neuropathy manifested with a subjective decrease in visual field, normal visual acuity, normal color vision, relative afferent pupillary defect, increased cupping of the optic nerve with focal neuroretinal rim defects, decreased nerve fiber layer thickness, and nerve fiber bundle-type visual field defects. The subject had no other risk factors for optic neuropathy. No other cause of neuropathy was identified.
CONCLUSIONS: Optic neuropathy is a potential vision-threatening complication of LASIK surgery. This complication may be due to barotrauma or ischemia related to extreme elevation of intraocular pressure by the suction ring. Careful examination of the optic nerve before and after LASIK surgery is warranted.
Can J Ophthalmol. 2007 Feb;42(1):123-4.
Optic pit maculopathy after laser-assisted in situ keratomileusis.
Rodriguez-Coleman H, Schiff WM, Hwang JC, Speaker MG.
National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
CASE REPORT: Optic disc pit is an embryological malformation of the optic nerve that occurs in less than one in 10,000 people. It is 10%-15% bilateral, and 25% to 70% of patients develop a neurosensory macular detachment within the 2nd to 4th decade. COMMENTS: We report a case of unilateral optic disc pit maculopathy 2 months after laser-assisted in situ keratomileusis (LASIK) revision.
Ophthalmic Surg Lasers Imaging. 2003 Jul-Aug;34(4):334-41.
Acute conformational changes in the optic nerve head with rapid intraocular pressure elevation: implications for LASIK surgery.
Piette S, Liebmann JM, Ishikawa H, Gürses-Ozden R, Buxton D, Ritch R.
Department of Ophthalmology, The New York Eye and Ear Infirmary, New York 10003, USA.
BACKGROUND AND OBJECTIVE: To investigate the effects of acute intraocular pressure (IOP) elevation on optic disc morphology.
PATIENTS AND METHODS: Ophthalmodynamometry was used to increase the IOP of normal, healthy eyes. Confocal scanning laser ophthalmoscopy of the optic nerve head using the Heidelberg Retinal Tomograph II (Heidelberg GmbH, Heidelberg, Germany) and IOP measurements were obtained before, during, and after IOP elevation.
RESULTS: Sixteen eyes of 16 normal volunteers (mean age, 32.8 +/- 11.9 years) were enrolled. Rim area, rim volume, cup area, cup volume, cup-to-disc ratio, mean cup depth, maximum cup depth, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area showed significant changes during IOP elevation (all P < .05, paired t test). All measured parameters returned to their original values after pressure resolution (all P > .2) except mean RNFL thickness (P = .03).
CONCLUSION: Transient elevation of IOP results in measurable alterations in optic nerve head topography.
J Cataract Refract Surg. 2000 Nov;26(11):1581-4.
Optic neuropathy associated with laser in situ keratomileusis.
Lee AG, Kohnen T, Ebner R, Bennett JL, Miller NR, Carlow TJ, Koch DD.
Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.
PURPOSE: To report 4 cases of optic neuropathy following laser in situ keratomileusis (LASIK).
SETTING: Tertiary Care ophthalmic practices.
METHODS: In this retrospective observational case series, 4 patients who developed acute visual loss following LASIK are reported. All had clinical evidence of optic neuropathy. Two had optic disc edema and 2 had normal appearing optic discs initially. None of the patients experienced significant visual recovery, and all developed optic atrophy in the affected eye.
RESULTS: All patients had evaluations for alternative etiologies of their optic neuropathy, with negative results. All patients were therefore presumed to have experienced an ischemic optic neuropathy following LASIK.
CONCLUSIONS: Patients who have LASIK may experience an acute anterior or retrobulbar optic neuropathy. The etiology is unknown but may be related to the marked increase in intraocular pressure that occurs during a portion of the procedure.
Disclaimer: The information contained on this web site is presented for the purpose of warning people about LASIK complications prior to surgery. LASIK patients experiencing problems should seek the advice of a physician.